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Zafeiropoulos S, Ahmed U, Bikou A, Mughrabi IT, Stavrakis S, Zanos S. Vagus nerve stimulation for cardiovascular diseases: Is there light at the end of the tunnel? Trends Cardiovasc Med 2024; 34:327-337. [PMID: 37506989 DOI: 10.1016/j.tcm.2023.07.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 06/12/2023] [Accepted: 07/17/2023] [Indexed: 07/30/2023]
Abstract
Autonomic dysfunction and chronic inflammation contribute to the pathogenesis and progression of several cardiovascular diseases (CVD), such as heart failure with preserved ejection fraction, atherosclerotic CVD, pulmonary arterial hypertension, and atrial fibrillation. The vagus nerve provides parasympathetic innervation to the heart, vessels, and lungs, and is also implicated in the neural control of inflammation through a neuroimmune pathway involving the spleen. Stimulation of the vagus nerve (VNS) can in principle restore autonomic balance and suppress inflammation, with potential therapeutic benefits in these diseases. Although VNS ameliorated CVD in several animal models, early human studies have demonstrated variable efficacy. The purpose of this review is to discuss the rationale behind the use of VNS in the treatment of CVD, to critically review animal and human studies of VNS in CVD, and to propose possible means to overcome the challenges in the clinical translation of VNS in CVD.
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Affiliation(s)
- Stefanos Zafeiropoulos
- Elmezzi Graduate School of Molecular Medicine at Northwell Health, Manhasset, NY, USA; Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, USA
| | - Umair Ahmed
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, USA
| | - Alexia Bikou
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, USA
| | - Ibrahim T Mughrabi
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, USA
| | - Stavros Stavrakis
- Heart Rhythm Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Stavros Zanos
- Elmezzi Graduate School of Molecular Medicine at Northwell Health, Manhasset, NY, USA; Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, USA.
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2
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Guo Y, Gharibani P. Analgesic Effects of Vagus Nerve Stimulation on Visceral Hypersensitivity: A Direct Comparison Between Invasive and Noninvasive Methods in Rats. Neuromodulation 2024; 27:284-294. [PMID: 37191611 DOI: 10.1016/j.neurom.2023.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 03/20/2023] [Accepted: 04/10/2023] [Indexed: 05/17/2023]
Abstract
OBJECTIVES The aims of this study were to investigate analgesic effects of vagus nerve stimulation (VNS) on visceral hypersensitivity (VH) in a rodent model of functional dyspepsia (FD) and to compare invasive VNS with noninvasive auricular VNS (aVNS). MATERIALS AND METHODS Eighteen ten-day-old male rats were gavaged with 0.1% iodoacetamide (IA) or 2% sucrose solution for six days. After eight weeks, IA-treated rats were implanted with electrodes for VNS or aVNS (n = 6 per group). Different parameters, varying in frequency and stimulation duty cycle, were tested to find the best parameter based on the improvement of VH assessed by electromyogram (EMG) during gastric distension. RESULTS Compared with sucrose-treated rats, visceral sensitivity was increased significantly in IA-treated "FD" rats and ameliorated remarkably by VNS (at 40, 60, and 80 mm Hg; p ≤ 0.02, respectively) and aVNS (at 60 and 80 mm Hg; p ≤ 0.05, respectively) with the parameter of 100 Hz and 20% duty cycle. There was no significant difference in area under the curve of EMG responses between VNS and aVNS (at 60 and 80 mm Hg, both p > 0.05). Spectral analysis of heart rate variability revealed a significant enhancement in vagal efferent activity while applying VNS/aVNS compared with sham stimulation (p < 0.01). In the presence of atropine, no significant differences were noted in EMG after VNS/aVNS. Naloxone blocked the analgesic effects of VNS/aVNS. CONCLUSIONS VNS/aVNS with optimized parameter elicits ameliorative effects on VH, mediated by autonomic and opioid mechanisms. aVNS is as effective as direct VNS and has great potential for treating visceral pain in patients with FD.
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Affiliation(s)
- Yu Guo
- Division of Gastroenterology and Hepatology, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Payam Gharibani
- Division of Gastroenterology and Hepatology, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Neurology, Division of Neuroimmunology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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Hadaya J, Dajani AH, Cha S, Hanna P, Challita R, Hoover DB, Ajijola OA, Shivkumar K, Ardell JL. Vagal Nerve Stimulation Reduces Ventricular Arrhythmias and Mitigates Adverse Neural Cardiac Remodeling Post-Myocardial Infarction. JACC Basic Transl Sci 2023; 8:1100-1118. [PMID: 37791302 PMCID: PMC10543930 DOI: 10.1016/j.jacbts.2023.03.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 03/29/2023] [Accepted: 03/29/2023] [Indexed: 10/05/2023]
Abstract
This study sought to evaluate the impact of chronic vagal nerve stimulation (cVNS) on cardiac and extracardiac neural structure/function after myocardial infarction (MI). Groups were control, MI, and MI + cVNS; cVNS was started 2 days post-MI. Terminal experiments were performed 6 weeks post-MI. MI impaired left ventricular mechanical function, evoked anisotropic electrical conduction, increased susceptibility to ventricular tachycardia and fibrillation, and altered neuronal and glial phenotypes in the stellate and dorsal root ganglia, including glial activation. cVNS improved cardiac mechanical function and reduced ventricular tachycardia/ventricular fibrillation post-MI, partly by stabilizing activation/repolarization in the border zone. MI-associated extracardiac neural remodeling, particularly glial activation, was mitigated with cVNS.
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Affiliation(s)
- Joseph Hadaya
- UCLA Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
- Molecular, Cellular, and Integrative Physiology Program, University of California, Los Angeles, Los Angeles, California, USA
| | - Al-Hassan Dajani
- UCLA Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Steven Cha
- UCLA Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Peter Hanna
- UCLA Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
- Molecular, Cellular, and Integrative Physiology Program, University of California, Los Angeles, Los Angeles, California, USA
| | - Ronald Challita
- UCLA Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Donald B. Hoover
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee, USA
- Center of Excellence in Inflammation, Infectious Disease and Immunity, East Tennessee State University, Johnson City, Tennessee, USA
| | - Olujimi A. Ajijola
- UCLA Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
- Molecular, Cellular, and Integrative Physiology Program, University of California, Los Angeles, Los Angeles, California, USA
| | - Kalyanam Shivkumar
- UCLA Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
- Molecular, Cellular, and Integrative Physiology Program, University of California, Los Angeles, Los Angeles, California, USA
| | - Jeffrey L. Ardell
- UCLA Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
- Molecular, Cellular, and Integrative Physiology Program, University of California, Los Angeles, Los Angeles, California, USA
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Bagić AI, Verner R, Afra P, Benbadis S. ASCEND: A randomized controlled trial of titration strategies for vagus nerve stimulation in drug-resistant epilepsy. Epilepsy Behav 2023; 145:109333. [PMID: 37429122 DOI: 10.1016/j.yebeh.2023.109333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 06/12/2023] [Accepted: 06/15/2023] [Indexed: 07/12/2023]
Abstract
Vagus Nerve Stimulation (VNS) therapy is widely understood to provide clinically meaningful improvements in seizure control to patients with drug-resistant epilepsy, and has been a staple in the clinical armamentaria available to epileptologists for over 25 years. Despite the long history of evidence-based reviews by neurology professional societies, there is still evidence of a practice gap in VNS titration and dosing that aims to maximize clinical benefit. Recent retrospective analyses have strongly argued for a more consistent application of a population-wide target dose of VNS, and further argued the importance of quickly achieving this target dose to hasten the onset of clinical benefits; however, these analyses failed to provide evidence for practical implementation. Herein, we describe a randomized controlled trial assessing the impact of titrating VNS according to three different protocols to achieve the target dose of 1.5 mA at 500µsec, for a 20-Hz signal frequency. The study was registered as NCT02385526 on March 11, 2015. Sixty-two patients were randomized into treatment groups that followed different titration protocols. One protocol (Group A) was designed to align with currently accepted professional guidance for VNS titration and the manufacturer's labeling for VNS in epilepsy (Heck et al., 2002), while the other two protocols were derived from VNS applications in other therapeutic areas. Group A participants were most likely to achieve the target dose parameters in 12 weeks or less (81.8%), with a median time-until-achievement of the target dose of 8.1 weeks, while less than 60% of patients in other groups were able to achieve the same endpoint. Participants in all groups experienced low levels of transient tolerability concerns and adverse events, suggesting titration to the target dose in 12 weeks or less following the Group A protocol is generally acceptable to most patients. These findings indicate that patients receiving VNS for epilepsy can achieve the manufacturer-recommended dose range in 12 weeks or less. A wider implementation of the approach will likely improve the clinical impact of VNS on seizure control and prevent undertreatment.
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Affiliation(s)
- Anto I Bagić
- University of Pittsburgh Comprehensive Epilepsy Center (UPCEC), Department of Neurology, Pittsburgh, PA, USA.
| | - Ryan Verner
- LivaNova PLC (or a Subsidiary), Medical and Clinical Affairs, Houston, TX, USA.
| | - Pegah Afra
- University of Massachusetts Chan Medical School, Department of Neurology, Boston, MA, USA; University of Utah School of Medicine, Department of Neurology, Salt Lake City, UT, USA.
| | - Selim Benbadis
- University of South Florida, Department of Neurology, Tampa, USA.
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Elamin ABA, Forsat K, Senok SS, Goswami N. Vagus Nerve Stimulation and Its Cardioprotective Abilities: A Systematic Review. J Clin Med 2023; 12:jcm12051717. [PMID: 36902505 PMCID: PMC10003006 DOI: 10.3390/jcm12051717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 02/10/2023] [Accepted: 02/18/2023] [Indexed: 02/24/2023] Open
Abstract
Despite the vagus nerve stimulator (VNS) being used in neuroscience, it has recently been highlighted that it has cardioprotective functions. However, many studies related to VNS are not mechanistic in nature. This systematic review aims to focus on the role of VNS in cardioprotective therapy, selective vagus nerve stimulators (sVNS), and their functional capabilities. A systemic review of the current literature was conducted on VNS, sVNS, and their ability to induce positive effects on arrhythmias, cardiac arrest, myocardial ischemia/reperfusion injury, and heart failure. Both experimental and clinical studies were reviewed and assessed separately. Of 522 research articles retrieved from literature archives, 35 met the inclusion criteria and were included in the review. Literature analysis proves that combining fiber-type selectivity with spatially-targeted vagus nerve stimulation is feasible. The role of VNS as a tool for modulating heart dynamics, inflammatory response, and structural cellular components was prominently seen across the literature. The application of transcutaneous VNS, as opposed to implanted electrodes, provides the best clinical outcome with minimal side effects. VNS presents a method for future cardiovascular treatment that can modulate human cardiac physiology. However, continued research is needed for further insight.
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Affiliation(s)
| | - Kowthar Forsat
- College of Medicine, Ajman University, Ajman P.O. Box 346, United Arab Emirates
| | - Solomon Silas Senok
- College of Medicine, Ajman University, Ajman P.O. Box 346, United Arab Emirates
| | - Nandu Goswami
- Institute of Physiology (Gravitational Physiology and Medicine), Medical University of Graz, 8036 Graz, Austria
- College of Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai P.O. Box 505055, United Arab Emirates
- Correspondence:
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Garcia RG, Staley R, Aroner S, Stowell J, Sclocco R, Napadow V, Barbieri R, Goldstein JM. Optimization of respiratory-gated auricular vagus afferent nerve stimulation for the modulation of blood pressure in hypertension. Front Neurosci 2022; 16:1038339. [PMID: 36570845 PMCID: PMC9783922 DOI: 10.3389/fnins.2022.1038339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 11/14/2022] [Indexed: 12/13/2022] Open
Abstract
Background The objective of this pilot study was to identify frequency-dependent effects of respiratory-gated auricular vagus afferent nerve stimulation (RAVANS) on the regulation of blood pressure and heart rate variability in hypertensive subjects and examine potential differential effects by sex/gender or race. Methods Twenty hypertensive subjects (54.55 ± 6.23 years of age; 12 females and 8 males) were included in a within-person experimental design and underwent five stimulation sessions where they received RAVANS at different frequencies (i.e., 2 Hz, 10 Hz, 25 Hz, 100 Hz, or sham stimulation) in a randomized order. EKG and continuous blood pressure signals were collected during a 10-min baseline, 30-min stimulation, and 10-min post-stimulation periods. Generalized estimating equations (GEE) adjusted for baseline measures were used to evaluate frequency-dependent effects of RAVANS on heart rate, high frequency power, and blood pressure measures, including analyses stratified by sex and race. Results Administration of RAVANS at 100 Hz had significant overall effects on the reduction of heart rate (β = -2.03, p = 0.002). It was also associated with a significant reduction of diastolic (β = -1.90, p = 0.01) and mean arterial blood pressure (β = -2.23, p = 0.002) in Black hypertensive participants and heart rate in female subjects (β = -2.83, p = 0.01) during the post-stimulation period when compared to sham. Conclusion Respiratory-gated auricular vagus afferent nerve stimulation exhibits frequency-dependent rapid effects on the modulation of heart rate and blood pressure in hypertensive patients that may further differ by race and sex. Our findings highlight the need for the development of optimized stimulation protocols that achieve the greatest effects on the modulation of physiological and clinical outcomes in this population.
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Affiliation(s)
- Ronald G. Garcia
- Clinical Neuroscience Laboratory of Sex Differences in the Brain, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
- Innovation Center on Sex Differences in Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
- School of Medicine, Universidad de Santander, Bucaramanga, Colombia
| | - Rachel Staley
- Clinical Neuroscience Laboratory of Sex Differences in the Brain, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
- Innovation Center on Sex Differences in Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Sarah Aroner
- Clinical Neuroscience Laboratory of Sex Differences in the Brain, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
- Innovation Center on Sex Differences in Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Jessica Stowell
- Clinical Neuroscience Laboratory of Sex Differences in the Brain, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
- Innovation Center on Sex Differences in Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Roberta Sclocco
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
- Scott Schoen and Nancy Adams Discovery Center for Recovery from Chronic Pain, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, MA, United States
- Department of Gastroenterology and Center for Neurointestinal Health, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Vitaly Napadow
- Innovation Center on Sex Differences in Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
- Scott Schoen and Nancy Adams Discovery Center for Recovery from Chronic Pain, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, MA, United States
| | - Riccardo Barbieri
- Innovation Center on Sex Differences in Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano, Italy
- Department of Anesthesia and Critical Care, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Jill M. Goldstein
- Clinical Neuroscience Laboratory of Sex Differences in the Brain, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
- Innovation Center on Sex Differences in Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
- Department of Medicine, Harvard Medical School, Boston, MA, United States
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Yokota H, Edama M, Hirabayashi R, Sekine C, Otsuru N, Saito K, Kojima S, Miyaguchi S, Onishi H. Effects of Stimulus Frequency, Intensity, and Sex on the Autonomic Response to Transcutaneous Vagus Nerve Stimulation. Brain Sci 2022; 12:brainsci12081038. [PMID: 36009101 PMCID: PMC9405815 DOI: 10.3390/brainsci12081038] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 07/29/2022] [Accepted: 08/03/2022] [Indexed: 12/10/2022] Open
Abstract
This study aimed to determine how transcutaneous vagus nerve stimulation (tVNS) alters autonomic nervous activity by comparing the effects of different tVNS frequencies and current intensities. We also investigated the sex-dependent autonomic response to tVNS. Thirty-five healthy adult participants were stimulated using a tVNS stimulator at the left cymba conchae while sitting on a reclining chair; tVNS-induced waveform changes were then recorded for different stimulus frequencies (Experiment 1: 3.0 mA at 100 Hz, 25 Hz, 10 Hz, 1 Hz, and 0 Hz (no stimulation)) and current intensities (Experiment 2: 100 Hz at 3.0 mA, 1.0 mA, 0.2 mA (below sensory threshold), and 0 mA (no stimulation)) using an electrocardiogram. Pulse widths were set at 250 µs in both experiment 1 and 2. Changes in heart rate (HR), root-mean-square of the difference between two successive R waves (RMSSD), and the ratio between low-frequency (LF) (0.04–0.15 Hz) and high-frequency (HF) (0.15–0.40 Hz) bands (LF/HF) in spectral analysis, which indicates sympathetic and parasympathetic activity, respectively, in heart rate variability (HRV), were recorded for analysis. Although stimulation at all frequencies significantly reduced HR (p = 0.001), stimulation at 100 Hz had the most pronounced effect (p = 0.001) in Experiment 1 and was revealed to be required to deliver at 3.0 mA in Experiment 2 (p = 0.003). Additionally, participants with higher baseline sympathetic activity experienced higher parasympathetic response during stimulation, and sex differences may exist in the autonomic responses by the application of tVNS. Therefore, our findings suggest that optimal autonomic changes induced by tVNS to the left cymba conchae vary depending on stimulating parameters and sex.
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Affiliation(s)
- Hirotake Yokota
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata 950-3198, Japan
- Department of Physical Therapy, Niigata University of Health and Welfare, Niigata 950-3198, Japan
- Correspondence: ; Tel.: +81-25-257-4723
| | - Mutsuaki Edama
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata 950-3198, Japan
- Department of Physical Therapy, Niigata University of Health and Welfare, Niigata 950-3198, Japan
| | - Ryo Hirabayashi
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata 950-3198, Japan
- Department of Physical Therapy, Niigata University of Health and Welfare, Niigata 950-3198, Japan
| | - Chie Sekine
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata 950-3198, Japan
- Department of Physical Therapy, Niigata University of Health and Welfare, Niigata 950-3198, Japan
| | - Naofumi Otsuru
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata 950-3198, Japan
- Department of Physical Therapy, Niigata University of Health and Welfare, Niigata 950-3198, Japan
| | - Kei Saito
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata 950-3198, Japan
- Department of Physical Therapy, Niigata University of Health and Welfare, Niigata 950-3198, Japan
| | - Sho Kojima
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata 950-3198, Japan
- Department of Physical Therapy, Niigata University of Health and Welfare, Niigata 950-3198, Japan
| | - Shota Miyaguchi
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata 950-3198, Japan
- Department of Physical Therapy, Niigata University of Health and Welfare, Niigata 950-3198, Japan
| | - Hideaki Onishi
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata 950-3198, Japan
- Department of Physical Therapy, Niigata University of Health and Welfare, Niigata 950-3198, Japan
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Konstam MA, Mann DL, Udelson JJE, Ardell JL, De Ferrari GM, Cowie MR, Klein HU, Gregory DD, Massaro JM, Libbus I, DiCarlo LA, Butler J, Parker JD, Teerlink JR. Advances in Our Clinical Understanding of Autonomic Regulation Therapy Using Vagal Nerve Stimulation in Patients Living With Heart Failure. Front Physiol 2022; 13:857538. [PMID: 35530511 PMCID: PMC9068946 DOI: 10.3389/fphys.2022.857538] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 03/21/2022] [Indexed: 11/17/2022] Open
Abstract
The ANTHEM-HF, INOVATE-HF, and NECTAR-HF clinical studies of autonomic regulation therapy (ART) using vagus nerve stimulation (VNS) systems have collectively provided dose-ranging information enabling the development of several working hypotheses on how stimulation frequency can be utilized during VNS for tolerability and improving cardiovascular outcomes in patients living with heart failure (HF) and reduced ejection fraction (HFrEF). Changes in heart rate dynamics, comprising reduced heart rate (HR) and increased HR variability, are a biomarker of autonomic nerve system engagement and cardiac control, and appear to be sensitive to VNS that is delivered using a stimulation frequency that is similar to the natural operating frequency of the vagus nerve. Among prior studies, the ANTHEM-HF Pilot Study has provided the clearest evidence of autonomic engagement with VNS that was delivered using a stimulation frequency that was within the operating range of the vagus nerve. Achieving autonomic engagement was accompanied by improvement from baseline in six-minute walk duration (6MWD), health-related quality of life, and left ventricular EF (LVEF), over and above those achieved by concomitant guideline-directed medical therapy (GDMT) administered to counteract harmful neurohormonal activation, with relative freedom from deleterious effects. Autonomic engagement and positive directional changes have persisted over time, and an exploratory analysis suggests that improvement in autonomic tone, symptoms, and physical capacity may be independent of baseline NT-proBNP values. Based upon these encouraging observations, prospective, randomized controlled trials examining the effects on symptoms and cardiac function as well as natural history have been warranted. A multi-national, large-scale, randomized, controlled trial is well underway to determine the outcomes associated with ART using autonomic nervous system engagement as a guide for VNS delivery.
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Affiliation(s)
- Marvin A Konstam
- The CardioVascular Center at Tufts Medical Center, Boston, MA, United States
| | - Douglas L Mann
- Center for Cardiovascular Research, Washington University School of Medicine, Saint Louis, MO, United States
| | | | - Jeffrey L Ardell
- UCLA Neurocardiology Program of Excellence, University of California, Los Angeles, Los Angeles, CA, United States
| | | | - Martin R Cowie
- School of Cardiovascular Medicine and Sciences, King's College London, London, United Kingdom
| | - Helmut U Klein
- Division of Cardiology, University of Rochester Medical Center, Rochester, NY, United States
| | - Douglas D Gregory
- Clinical Cardiovascular Science Foundation, Boston, MA, United States
| | - Joseph M Massaro
- Department of Biostatistics, School of Public Health, Boston University, Boston, MA, United States
| | - Imad Libbus
- LivaNova USA Incorporated, Houston, TX, United States
| | | | - Javed Butler
- Department of Medicine, University of Mississippi Medical Center, Jackson, MS, United States
| | - John D Parker
- University of Toronto, University Health Network, Toronto, ON, Canada
| | - John R Teerlink
- Section of Cardiology, San Francisco Veterans Affairs Medical Center and School of Medicine, University of California, San Francisco, San Francisco, CA, United States
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9
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Ottaviani MM, Vallone F, Micera S, Recchia FA. Closed-Loop Vagus Nerve Stimulation for the Treatment of Cardiovascular Diseases: State of the Art and Future Directions. Front Cardiovasc Med 2022; 9:866957. [PMID: 35463766 PMCID: PMC9021417 DOI: 10.3389/fcvm.2022.866957] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 03/14/2022] [Indexed: 01/07/2023] Open
Abstract
The autonomic nervous system exerts a fine beat-to-beat regulation of cardiovascular functions and is consequently involved in the onset and progression of many cardiovascular diseases (CVDs). Selective neuromodulation of the brain-heart axis with advanced neurotechnologies is an emerging approach to corroborate CVDs treatment when classical pharmacological agents show limited effectiveness. The vagus nerve is a major component of the cardiac neuroaxis, and vagus nerve stimulation (VNS) is a promising application to restore autonomic function under various pathological conditions. VNS has led to encouraging results in animal models of CVDs, but its translation to clinical practice has not been equally successful, calling for more investigation to optimize this technique. Herein we reviewed the state of the art of VNS for CVDs and discuss avenues for therapeutic optimization. Firstly, we provided a succinct description of cardiac vagal innervation anatomy and physiology and principles of VNS. Then, we examined the main clinical applications of VNS in CVDs and the related open challenges. Finally, we presented preclinical studies that aim at overcoming VNS limitations through optimization of anatomical targets, development of novel neural interface technologies, and design of efficient VNS closed-loop protocols.
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Affiliation(s)
- Matteo Maria Ottaviani
- Institute of Life Sciences, Scuola Superiore Sant’Anna, Pisa, Italy
- Department of Excellence in Robotics and Artificial Intelligence, The BioRobotics Institute, Scuola Superiore Sant’Anna, Pisa, Italy
| | - Fabio Vallone
- Department of Excellence in Robotics and Artificial Intelligence, The BioRobotics Institute, Scuola Superiore Sant’Anna, Pisa, Italy
| | - Silvestro Micera
- Department of Excellence in Robotics and Artificial Intelligence, The BioRobotics Institute, Scuola Superiore Sant’Anna, Pisa, Italy
- Bertarelli Foundation Chair in Translational Neural Engineering, Center for Neuroprosthetics, Institute of Bioengineering, Ecole Polytechnique Federale de Lausanne, Lausanne, Switzerland
| | - Fabio A. Recchia
- Institute of Life Sciences, Scuola Superiore Sant’Anna, Pisa, Italy
- Fondazione Toscana Gabriele Monasterio, Pisa, Italy
- Department of Physiology, Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States
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Libbus I, Premchand RK, Sharma K, Mittal S, Monteiro R, Amurthur B, KenKnight BH, DiCarlo LA, Anand IS. Persistent Autonomic Engagement and Cardiac Control After Four or More Years of Autonomic Regulation Therapy Using Vagus Nerve Stimulation. Front Physiol 2022; 13:853617. [PMID: 35360224 PMCID: PMC8963780 DOI: 10.3389/fphys.2022.853617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 02/16/2022] [Indexed: 11/13/2022] Open
Abstract
Introduction Although heart failure (HF) outcomes have improved dramatically with the use of guideline directed medical therapy and implantable devices, the overall prognosis of patients with HF and reduced ejection fraction (HFrEF) remains poor. Autonomic Regulation Therapy (ART) using chronic vagus nerve stimulation (VNS) has been evaluated in the ANTHEM-HF study, using changes in heart rate (HR) dynamics as a biomarker of autonomic nervous system engagement and cardiac control to guide VNS titration. ART was associated with sustained improvement in cardiac function and HF symptoms in patients with HFrEF and persistent HF symptoms despite guideline-directed medical therapy (GDMT). We sought to determine whether the responsiveness of the autonomic nervous system to ART, as reflected in HR response to vagus stimulation during the VNS duty cycle, is maintained after long-term chronic VNS administration. Methods Fifteen patients with HFrEF and implanted with a VNS systems in the ANTHEM-HF study were evaluated after 4.7 ± 0.3 years (range: 4.0-5.0 years) of chronic ART. ECG electrodes were placed on each patient's wrists, and ECG rhythm strips were recorded. Instantaneous HR time series was computed at each patient's chronically programmed VNS intensity and during progressively increasing VNS intensity. HR during active stimulation (on-time) was compared to HR just prior to initiation of each stimulation cycle (off-time). Results Persistent autonomic engagement was observed in a majority of patients (11 of 15, 73%) after chronic ART for four or more years. The average magnitude of HR reduction during ART on-time in all patients was 2.4 ± 3.2 bpm at the chronically programmed VNS pulse parameter settings. Conclusion Autonomic responsiveness to VNS persists in patients with HFrEF who received chronic ART for up to 5 years as a supplement to GDMT. This suggests that the effects of ART on autonomic engagement and cardiac control remain durable over time. Clinical Trial Registration [ClinicalTrials.gov], identifier [#NCT01823887, CTRI registration #CTRI/2012/05/002681].
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Affiliation(s)
- Imad Libbus
- LivaNova USA, Inc., Houston, TX, United States
| | | | - Kamal Sharma
- Sanjivani Super Specialty Hospitals, Ahmedabad, India
| | | | | | | | | | | | - Inder S. Anand
- Emeritus, University of Minnesota, Minneapolis, MN, United States
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11
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Cooper CM, Farrand AQ, Andresen MC, Beaumont E. Vagus nerve stimulation activates nucleus of solitary tract neurons via supramedullary pathways. J Physiol 2021; 599:5261-5279. [PMID: 34676533 DOI: 10.1113/jp282064] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 10/12/2021] [Indexed: 01/20/2023] Open
Abstract
Vagus nerve stimulation (VNS) treats patients with drug-resistant epilepsy, depression and heart failure, but the mechanisms responsible are uncertain. The mild stimulus intensities used in chronic VNS suggest activation of myelinated primary visceral afferents projecting to the nucleus of the solitary tract (NTS). Here, we monitored the activity of second and higher order NTS neurons in response to peripheral vagal activation using therapeutic VNS criteria. A bipolar stimulating electrode activated the left cervical vagus nerve, and stereotaxically placed single tungsten electrodes recorded unit activity from the left caudomedial NTS of chloralose-anaesthetized rats. High-intensity single electrical stimuli established vagal afferent conduction velocity (myelinated A-type or unmyelinated C-type) as well as synaptic order (second vs. higher order using paired electrical stimuli) for inputs to single NTS neurons. Then, VNS treatment was applied. A mid-collicular knife cut (KC) divided the brainstem from all supramedullary regions to determine their contribution to NTS activity. Our chief findings indicate that the KC reduced basal spontaneous activity of second-order NTS neurons receiving myelinated vagal input by 85%. In these neurons, acute VNS increased activity similarly in Control and KC animals. Interestingly, the KC interrupted VNS activation of higher order NTS neurons and second-order NTS neurons receiving unmyelinated vagal input, indicating that supramedullary descending projections to NTS are needed to amplify the peripheral neuronal signal from VNS. The present study begins to define the pathways activated during VNS and will help to better identify the central nervous system contributions to the therapeutic benefits of VNS therapy. KEY POINTS: Vagus nerve stimulation is routinely used in the clinic to treat epilepsy and depression, despite our uncertainty about how this treatment works. For this study, the connections between the nucleus of the solitary tract (NTS) and the higher brain regions were severed to learn more about their contribution to activity of these neurons during stimulation. Severing these brain connections reduced baseline activity as well as reducing stimulation-induced activation for NTS neurons receiving myelinated vagal input. Higher brain regions play a significant role in maintaining both normal activity in NTS and indirect mechanisms of enhancing NTS neuronal activity during vagus nerve stimulation.
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Affiliation(s)
- Coty M Cooper
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA
| | - Ariana Q Farrand
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA
| | | | - Eric Beaumont
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA
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12
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Maharjan A, Peng M, Cakmak YO. The effects of frequency-specific, non-invasive, median nerve stimulation on food-related attention and appetite. Appetite 2021; 169:105807. [PMID: 34798222 DOI: 10.1016/j.appet.2021.105807] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 11/11/2021] [Accepted: 11/12/2021] [Indexed: 12/17/2022]
Abstract
Median nerve stimulation (MNS) in the existing literature has been used for treating gastrointestinal disorders and amelioration of nausea and vomiting. Recently, studies have shown that MNS can also exert effects on olfactory performances and corresponding anatomical regions through the activation of vagal pathways. This study aimed to test effects of specific frequencies of MNS on food-related attention and appetite. The experiment used an odourised, dot probe task for testing food-related attention and a combination of behavioural (i.e., visual analogue scales; VAS) and physiological approaches (i.e., electrocardiograph; ECG - root mean square of successive differences between normal heartbeats-RMSSD: parasympathetic nervous system activation (RMSSD), stress index-SI: sympathetic nervous system activation) for measuring hunger, appetite, and satiation. Twenty-four healthy, male adults completed a VAS and dot probe task before and after receiving either 40 Hz-, 80 Hz-, 120 Hz MNS or sham (control) across four different sessions with continuous ECG recording throughout each session. Data from the dot probe task were analysed using repeated-measures ANOVA, while pair-wise tests were used for ECG recordings and VAS. Improvements on the dot probe task, not specific to odour-food congruence were found after 40 Hz MNS (p-value = 0.048; strong effect size (0.308 partial eta squared)) while increased ratings of hunger (VAS) (p-value = 0.03, small effect size (0.47 Cohen-D)) and RMSSD scores (p-value < 0.001; medium effect size (0.76 Cohen-D)) were found after 120 Hz MNS. These findings implore further testing of MNS frequency parameters on improving RMSSD, a characteristic marker of measuring parasympathetic/autonomic nervous system activation pertaining to the vagal network. Furthermore, improving sympathovagal balance is associated with cardiovascular benefits in numerous health-related conditions such as obesity, hypertension and diabetes.
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Affiliation(s)
- Ashim Maharjan
- Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Mei Peng
- Sensory Neuroscience Laboratory, Department of Food Science, University of Otago, Dunedin, New Zealand
| | - Yusuf O Cakmak
- Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand; Brain Health Research Centre, Dunedin, New Zealand; Medical Technologies Centre of Research Excellence, Auckland, New Zealand.
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Dede E, Gregory DD, Ardell JL, Libbus I, DiCarlo LA, Premchand RK, Sharma K, Mittal S, Monteiro R, Anand IS, Düngen HD. Therapeutic responsiveness to vagus nerve stimulation in patients receiving beta-blockade for heart failure with reduced ejection fraction. IJC HEART & VASCULATURE 2021; 37:100888. [PMID: 34754899 PMCID: PMC8556756 DOI: 10.1016/j.ijcha.2021.100888] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 08/19/2021] [Accepted: 10/06/2021] [Indexed: 12/23/2022]
Abstract
Background The effect of beta-blockade (BB) on response to vagus nerve stimulation (VNS) has not been reported in patients with heart failure and reduced ejection fraction (HFrEF). In the ANTHEM-HF Study, 60 patients received chronic cervical VNS. Background pharmacological therapy remained unchanged during the study, and VNS intensity was stable once up-titrated. Significant improvement from baseline occurred in resting 24-hour heart rate (HR), 24-hour HR variability (SDNN), left ventricular EF (LVEF), 6-minute walk distance (6MWD), and quality of life (MLWHFS) at 6 months post-titration. We evaluated whether response to VNS was related to percentage of target BB dose (PTBBD) at baseline. Methods Patients were categorized by baseline PTBBD, then analyzed for changes from baseline in symptoms and function at 6 months after VNS titration. Results All patients received BB, either PTBBD ≥ 50 % (16 patients, 27 %; group 1) or PTBBD < 50 % (44 patients, 73 %; group 2). Heart rate, systolic blood pressure, LVEF, use of ACE/ARB, and use of MRA were similar between the two groups at baseline. Six months after up-titration, VNS reduced HR and significantly improved SDNN, LVEF, 6MWD, and MLWHFS equally in both groups. Conclusions In the ANTHEM-HF study, VNS responsiveness appeared to be independent of the baseline BB dose administered.
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Affiliation(s)
- Enea Dede
- Charité Universitätsmedizin Berlin, Germany
| | | | | | | | | | | | - Kamal Sharma
- Sanjivani Super Specialty Hospitals, Ahmedabad, India
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14
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Abstract
Vagal nerve stimulation (VNS) has a strong pathophysiological rationale as a potentially beneficial treatment for heart failure with reduced ejection fraction. Despite several promising preclinical studies and pilot clinical studies, the two large, controlled trials—NECTAR-HF and INOVATE-HF—failed to demonstrate the expected benefit. It is likely that clinical application of VNS in phase III studies was performed before a sufficient degree of understanding of the complex pathophysiology of autonomic electrical modulation had been achieved, therefore leading to an underestimation of its potential benefit. More knowledge on the complex dose–response issue of VNS (i.e., pulse amplitude, frequency, duration and duty cycle) has been gathered since these trials and a new randomized study is currently underway with an adaptive design and a refined approach in an attempt to deliver the proper dose to a more selected group of patients.
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Affiliation(s)
- Veronica Dusi
- Division of Cardiology, Department of Medical Sciences, Citta della Salute e della Scienza Hospital, University of Turin, Corso Bramante 88, 10126, Turin, Italy.
| | - Gaetano Maria De Ferrari
- Division of Cardiology, Department of Medical Sciences, Citta della Salute e della Scienza Hospital, University of Turin, Corso Bramante 88, 10126, Turin, Italy
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15
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Hsieh CM, Lin WC, Peng HY, Chen HC, Ho YC, Li CJ, Wu XG, Chung JY, Lee SD, Lin TB. Shoulder transcutaneous electric nerve stimulation decreases heart rate via potentiating vagal tone. Sci Rep 2021; 11:19168. [PMID: 34580404 PMCID: PMC8476641 DOI: 10.1038/s41598-021-98690-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Accepted: 09/07/2021] [Indexed: 11/23/2022] Open
Abstract
By enhancing vagal activity, auricle transcutaneous electric nerve stimulation (TENS) is developed as a non-invasive therapy for heart failure. Nevertheless, though shoulder TENS used for treating adhesive capsulitis could affect vagal tone, its potential impact on heart functions remains unclear. In this study, electrocardiogram (ECG) and heart rate (HR) of subjects in response to sham, right-sided, or left-sided shoulder TENS (TENS-S, TENS-R, and TENS-L, respectively; 5 min) were recorded and analyzed. During the stimulation period, TENS-R constantly and TENS-L transiently decreased the HR of subjects; both TENS-R and TENS-L increased powers of the low- and high-frequency spectra. While TENS-R exhibiting no effect, TENS-L increased the ratio of low/high-frequency power spectrum indicating TENS-R decreased the HR through potentiating cardiac vagal tone. Collectively, these results suggest TENS could be an early and non-invasive therapy for heart failure patients before considering implant devices or devices are not feasible; moreover, therapists/physicians need to carefully monitor the potential adverse events during treatment for patient safety. Trial registration: The study protocol was registered in ClinicalTrials.gov (NCT03982472; 11/06/2019).
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Affiliation(s)
- Chun-Ming Hsieh
- Division of Physical Therapy, St. Paul's Hospital, Taoyuan, Taiwan
| | - Wan-Chen Lin
- Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, No. 250, Wu-Hsing Street, Taipei, 11031, Taiwan.,National Taiwan University Hospital, Taipei, Taiwan
| | - Hsien-Yu Peng
- Department of Medicine, Mackay Medical College, New Taipei, Taiwan
| | - Huang-Chung Chen
- Department of Rehabilitation, St. Paul's Hospital, Taoyuan, Taiwan
| | - Yu-Cheng Ho
- Department of Medicine, Mackay Medical College, New Taipei, Taiwan
| | - Chi-Jui Li
- Division of Physical Therapy, St. Paul's Hospital, Taoyuan, Taiwan
| | - Xi-Guan Wu
- Division of Physical Therapy, St. Paul's Hospital, Taoyuan, Taiwan
| | - Jen-Yi Chung
- Division of Physical Therapy, St. Paul's Hospital, Taoyuan, Taiwan
| | - Shin-Da Lee
- Department of Occupational Therapy, Asia University, Taichung, Taiwan.,Department of Physical Therapy, Graduate Institute of Rehabilitation Science, China Medical University, Taichung, Taiwan.,School of Rehabilitation Science, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Tzer-Bin Lin
- Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, No. 250, Wu-Hsing Street, Taipei, 11031, Taiwan. .,Department of Bioinformatics and Medical Engineering, Asia University, Taichung, Taiwan. .,Department of Biotechnology, Asia University, Taichung, Taiwan. .,Cell Physiology and Molecular Image Research Center, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.
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16
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Implantable vagus nerve stimulation system performance is not affected by internal or external defibrillation shocks. J Interv Card Electrophysiol 2021; 63:555-560. [PMID: 34467496 PMCID: PMC9151504 DOI: 10.1007/s10840-021-01050-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 08/09/2021] [Indexed: 11/29/2022]
Abstract
Purpose Autonomic regulation therapy (ART) for heart failure (HF) is delivered using vagus nerve stimulation (VNS), and has been associated with improvement in cardiac function and HF symptoms. VNS is delivered using an implantable pulse generator (IPG) and a lead placed around the cervical vagus nerve. Because HF patients may receive concomitant cardiac defibrillation therapy, testing was conducted to determine the effect of defibrillation (DF) on VNS system performance. Methods Normal swine (n = 4) with VNS system implants on the right cervical vagus nerve received sequential defibrillation shocks with three defibrillation systems: an implantable cardioverter defibrillator (ICD), a subcutaneous ICD (S-ICD), and an external cardioverter defibrillator (ECD). Each system delivered a series of bipolar high-energy shocks and reverse-polarity high-energy shocks. Results The specified cardiac defibrillation shocks were delivered successfully from each of the three defibrillation systems to all animals. After each shock series, interrogation of the IPG confirmed that software and data were unchanged from pre-programmed values. After all of the defibrillation shocks were delivered, the IPGs underwent and passed comprehensive electrical testing demonstrating proper system function. No shifts in IPG parameters or ART system failures were observed, and histologic evaluation of the vagus nerve revealed no anatomic changes. Conclusions Implantable VNS systems were tested in vivo for immunity to defibrillation via ICD, S-ICD, and ECD, and were found to be unaffected by a series of high-energy defibrillation shocks. These results confirm that ART systems are capable of continuing to function after defibrillation and the cervical vagus nerve is anatomically unaffected.
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Short-Term Effects of Vagus Nerve Stimulation on Learning and Evoked Activity in Auditory Cortex. eNeuro 2021; 8:ENEURO.0522-20.2021. [PMID: 34088737 PMCID: PMC8240839 DOI: 10.1523/eneuro.0522-20.2021] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 04/13/2021] [Accepted: 04/16/2021] [Indexed: 11/21/2022] Open
Abstract
Chronic vagus nerve stimulation (VNS) has been shown to facilitate learning, but effects of acute VNS on neural coding and behavior remain less well understood. Ferrets implanted with cuff electrodes on the vagus nerve were trained by classical conditioning on an auditory tone frequency-reward association. One tone was associated with reward while another tone was not. Tone frequencies and reward associations were changed every 2 d, requiring learning of a new relationship. When tones were paired with VNS, animals consistently learned the new association within 2 d. When VNS occurred randomly between trials, learning within 2 d was unreliable. In passively listening animals, neural activity in primary auditory cortex (A1) and pupil size were recorded before and after acute VNS-tone pairing. After pairing with a neuron’s best-frequency (BF) tone, responses by a subpopulation of neurons were reduced. VNS paired with an off-BF tone or during intertrial intervals had no effect. The BF-specific reduction in neural responses after VNS remained, even after regressing out changes explained by pupil-indexed arousal. VNS induced brief dilation in the pupil, and the size of this change predicted the magnitude of persistent changes in the neural response. This interaction suggests that fluctuations in neuromodulation associated with arousal gate the long-term VNS effects on neural activity.
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Cracchiolo M, Ottaviani MM, Panarese A, Strauss I, Vallone F, Mazzoni A, Micera S. Bioelectronic medicine for the autonomic nervous system: clinical applications and perspectives. J Neural Eng 2021; 18. [PMID: 33592597 DOI: 10.1088/1741-2552/abe6b9] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 02/16/2021] [Indexed: 12/11/2022]
Abstract
Bioelectronic medicine (BM) is an emerging new approach for developing novel neuromodulation therapies for pathologies that have been previously treated with pharmacological approaches. In this review, we will focus on the neuromodulation of autonomic nervous system (ANS) activity with implantable devices, a field of BM that has already demonstrated the ability to treat a variety of conditions, from inflammation to metabolic and cognitive disorders. Recent discoveries about immune responses to ANS stimulation are the laying foundation for a new field holding great potential for medical advancement and therapies and involving an increasing number of research groups around the world, with funding from international public agencies and private investors. Here, we summarize the current achievements and future perspectives for clinical applications of neural decoding and stimulation of the ANS. First, we present the main clinical results achieved so far by different BM approaches and discuss the challenges encountered in fully exploiting the potential of neuromodulatory strategies. Then, we present current preclinical studies aimed at overcoming the present limitations by looking for optimal anatomical targets, developing novel neural interface technology, and conceiving more efficient signal processing strategies. Finally, we explore the prospects for translating these advancements into clinical practice.
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Affiliation(s)
- Marina Cracchiolo
- The BioRobotics Institute and Department of Excellence in Robotics & AI, The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Matteo Maria Ottaviani
- The BioRobotics Institute and Department of Excellence in Robotics & AI, The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Alessandro Panarese
- The BioRobotics Institute and Department of Excellence in Robotics & AI, The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Ivo Strauss
- The BioRobotics Institute and Department of Excellence in Robotics & AI, The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Fabio Vallone
- The BioRobotics Institute and Department of Excellence in Robotics & AI, The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Alberto Mazzoni
- The BioRobotics Institute and Department of Excellence in Robotics & AI, The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Silvestro Micera
- The BioRobotics Institute and Department of Excellence in Robotics & AI, The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy.,Bertarelli Foundation Chair in Translational NeuroEngineering, Centre for Neuroprosthetics and Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
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19
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Sharma K, Premchand RK, Mittal S, Monteiro R, Libbus I, DiCarlo LA, Ardell JL, Amurthur B, KenKnight BH, Anand IS. Long-term Follow-Up of Patients with Heart Failure and Reduced Ejection Fraction Receiving Autonomic Regulation Therapy in the ANTHEM-HF Pilot Study. Int J Cardiol 2020; 323:175-178. [PMID: 33038408 DOI: 10.1016/j.ijcard.2020.09.072] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 09/14/2020] [Accepted: 09/30/2020] [Indexed: 11/28/2022]
Abstract
BACKGROUND The ANTHEM-HF pilot study was an open-label study that evaluated the safety and feasibility of autonomic regulation therapy (ART) utilizing cervical vagus nerve stimulation (VNS) for patients with chronic HF with reduced EF (HFrEF). Patients in NYHA class II-III with EF ≤40% (n = 60) received ART for 6 months post-titration. ART was associated with sustained improvement in left ventricular (LV) function and HF symptoms at 6 and 12 months. METHODS Continuously cyclic VNS was maintained to determine longer-term safety and chronic effects of ART. Echocardiographic parameters and HF symptoms were assessed throughout a follow-up period of at least 42 months. RESULTS Between 12 and 42 months after initial titration, there were no device-related SAEs or malfunctions. There were 10 SAEs adjudicated to be unrelated to VNS, including 5 deaths. There were 6 non-serious adverse events that were adjudicated to be device-related (2 oropharyngeal pain, 1 implant site pain, 2 voice alteration, and 1 hoarseness). At 42 months, there was significant improvement from baseline in LVEF, NYHA class, 6-min walk distance, and MLHFQ score. However, these improvements at 42 months were not significantly different from mean values at 6 and 12 months. CONCLUSIONS In a 42-month follow-up, ART was durable, safe, and was associated with beneficial effects on LVEF and 6-min walk distance. Long term, chronic, open-loop ART continued to be well-tolerated in patients with HFrEF. The open label, randomized, controlled, ANTHEM-HFrEF Pivotal Study is currently underway to further evaluate ART in patients with advanced HF.
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Affiliation(s)
- Kamal Sharma
- Sanjivani Super Specialty Hospitals, Ahmedabad, India
| | | | | | | | - Imad Libbus
- LivaNova PLC, Inc., Houston, TX, United States of America
| | | | - Jeffrey L Ardell
- University of California at Los Angeles, Los Angeles, CA, United States of America
| | - Badri Amurthur
- LivaNova PLC, Inc., Houston, TX, United States of America
| | | | - Inder S Anand
- University of Minnesota, Minneapolis, MN, United States of America.
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20
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Anand I, Ardell JL, Gregory D, Libbus I, DiCarlo L, Premchand RK, Sharma K, Mittal S, Monteiro R. Baseline NT-proBNP and responsiveness to autonomic regulation therapy in patients with heart failure and reduced ejection fraction. IJC HEART & VASCULATURE 2020; 29:100520. [PMID: 32509959 PMCID: PMC7264752 DOI: 10.1016/j.ijcha.2020.100520] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 04/15/2020] [Indexed: 11/26/2022]
Abstract
Background Recent heart failure studies have associated lower baseline natriuretic peptide levels with improved morbidity/mortality outcomes during pharmaceutical treatment, and better clinical outcomes during neuromodulation (NM) with carotid nerve plexus stimulation for HFrEF when NT-proBNP < 1600 pg/ml. Whether baseline NT-proBNP is associated with HFrEF responsiveness to NM using vagus nerve stimulation (VNS) has not been examined. Hence, we evaluated the interaction of baseline NT-proBNP with changes in symptoms and function that occurred during chronic VNS in the ANTHEM-HF study. Methods A repeated measures, generalized-estimating, equations model evaluated the relationship of baseline NT-proBNP values above and below 1600 pg/ml to symptomatic and functional responses in ANTHEM-HF. Results Median (interquartile range; maximum) NT-proBNP was 868 (322, 1875; 14,656) pg/ml (N = 58). Heart rate (HR), HR variability (SDNN), 6-minute walk distance, MLWHF mean score, and NYHA improved significantly, independent of baseline NT-proBNP. While there was a statistical interaction between baseline NT-proBNP and better LVEF improvement during VNS, LVEF improved overall in the study cohort (N = 60; 32 ± 7 to 37 ± 10%; p = 0.0042), and in those patients whose baseline NT-proBNP was below the median baseline NT-proBNP value (n = 29; 36 ± 6 to 42 ± 10%; p < 0.0025)] or above this value (n = 29; 29 ± 7 to 32 ± 9%; p < 0.05). Conclusions In ANTHEM-HF, overall symptomatic and functional improvement during chronic VNS was independent of baseline NTproBNP. These are preliminary and hypothesis-generating findings, and the reason for a differing interaction between baseline NT-proBNP and response to CNPS and VNS remains unclear. It is anticipated that the ongoing ANTHEM-HFrEF Pivotal Study of VNS will provide additional insight.
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Affiliation(s)
- Inder Anand
- University of Minnesota (Emeritus), Minneapolis, MN, USA
| | | | - Doug Gregory
- Clinical Cardiovascular Science Foundation, Boston, MA, USA
| | | | | | | | - Kamal Sharma
- Sanjivani Super Specialty Hospitals, Ahmedabad, India
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Burger AM, D'Agostini M, Verkuil B, Van Diest I. Moving beyond belief: A narrative review of potential biomarkers for transcutaneous vagus nerve stimulation. Psychophysiology 2020; 57:e13571. [PMID: 32202671 DOI: 10.1111/psyp.13571] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 01/15/2020] [Accepted: 02/01/2020] [Indexed: 12/25/2022]
Abstract
Transcutaneous vagus nerve stimulation (tVNS) is a non-invasive neurostimulation technique that is currently being tested as a potential treatment for a myriad of neurological and psychiatric disorders. However, the working mechanisms underlying tVNS are poorly understood and it remains unclear whether stimulation activates the vagus nerve for every participant. Finding a biological marker of tVNS is imperative, as it can help guide research on clinical applications and can inform researchers on optimal stimulation sites and parameters to further optimize treatment efficacy. In this narrative review, we discuss five potential biomarkers for tVNS and review currently available evidence for these markers for both invasive and tVNS. While some of these biomarkers hold promise from a theoretical perspective, none of the potential biomarkers provide clear and definitive indications that tVNS increases the vagal activity or augments activity in the locus coeruleus-noradrenaline network. We conclude the review by providing several recommendations for how to tackle the challenges and opportunities when researching potential biomarkers for the effects of tVNS.
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Affiliation(s)
- Andreas Michael Burger
- Health Psychology Research Group, Faculty of Psychology and Educational Sciences, University of Leuven, Leuven, Belgium.,Biological Psychology Research Group, Faculty of Psychology and Educational Sciences, University of Leuven, Leuven, Belgium
| | - Martina D'Agostini
- Health Psychology Research Group, Faculty of Psychology and Educational Sciences, University of Leuven, Leuven, Belgium
| | - Bart Verkuil
- Department of Clinical Psychology, Leiden University, Leiden, the Netherlands
| | - Ilse Van Diest
- Health Psychology Research Group, Faculty of Psychology and Educational Sciences, University of Leuven, Leuven, Belgium
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22
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Capilupi MJ, Kerath SM, Becker LB. Vagus Nerve Stimulation and the Cardiovascular System. Cold Spring Harb Perspect Med 2020; 10:cshperspect.a034173. [PMID: 31109966 DOI: 10.1101/cshperspect.a034173] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The vagus nerve plays an important role in maintaining physiological homeostasis, which includes reflex pathways that regulate cardiac function. The link between vagus nerve activity and the high-frequency component of heart rate variability (HRV) has been well established, correlating with vagal tone. Recently, vagus nerve stimulation (VNS) has been investigated as a therapeutic for a multitude of diseases, such as treatment-resistant epilepsy, rheumatoid arthritis, Crohn's disease, and asthma. Because of the vagus nerve's innervation of the heart, VNS has been identified as a potential therapy for cardiovascular disorders, such as cardiac arrest, acute myocardial infarction, and stroke. Here, we review the current state of preclinical and clinical studies, as well as the potential application of VNS in relation to the cardiovascular system.
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Affiliation(s)
- Michael J Capilupi
- Department of Emergency Medicine, North Shore University Hospital, Northwell Health, Manhasset, New York 11030
| | - Samantha M Kerath
- Feinstein Institute for Medical Research, Northwell Health, Manhasset, New York 11030
| | - Lance B Becker
- Department of Emergency Medicine, North Shore University Hospital, Northwell Health, Manhasset, New York 11030.,Feinstein Institute for Medical Research, Northwell Health, Manhasset, New York 11030.,Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, New York 11549
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23
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Anand IS, Konstam MA, Klein HU, Mann DL, Ardell JL, Gregory DD, Massaro JM, Libbus I, DiCarlo LA, Udelson JJE, Butler J, Parker JD, Teerlink JR. Comparison of symptomatic and functional responses to vagus nerve stimulation in ANTHEM-HF, INOVATE-HF, and NECTAR-HF. ESC Heart Fail 2020; 7:75-83. [PMID: 31984682 PMCID: PMC7083506 DOI: 10.1002/ehf2.12592] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 11/11/2019] [Accepted: 11/25/2019] [Indexed: 12/19/2022] Open
Abstract
AIMS Clinical studies of vagal nerve stimulation (VNS) for heart failure with reduced ejection fraction have had mixed results to date. We sought to compare VNS delivery and associated changes in symptoms and function in autonomic regulation therapy via left or right cervical vagus nerve stimulation in patients with chronic heart failure (ANTHEM-HF), increase of vagal tone in heart failure (INOVATE-HF), and neural cardiac therapy for heart failure (NECTAR-HF) for hypothesis generation. METHODS AND RESULTS Descriptive statistics were used to analyse data from the public domain for differences in proportions using Pearson's chi-square test, differences in mean values using Student's unpaired t-test, and differences in changes of mean values using two-sample t-tests. Guideline-directed medical therapy recommendations were similar across studies. Fewer patients were in New York Heart Association 3, and baseline heart rate (HR) was higher in ANTHEM-HF. In INOVATE-HF, VNS was aimed at peripheral neural targets, using closed-loop delivery that required synchronization of VNS to R-wave sensing by an intracardiac lead. Pulse frequency was low (1-2 Hz) because of a timing schedule allowing ≤3 pulses of VNS following at most 25% of detected R waves. NECTAR-HF and ANTHEM-HF used open-loop VNS delivery (i.e. independent of any external signal) aimed at both central and peripheral targets. In NECTAR-HF, VNS delivery at 20 Hz caused off-target effects that limited VNS up-titration in a majority of patients. In ANTHEM-HF, VNS delivery at 10 Hz allowed up-titration until changes in HR dynamics were confirmed. Six months after VNS titration, significant improvements in both HR and HR variability occurred only in ANTHEM-HF. When ANTHEM-HF and NECTAR-HF were compared, greater improvements from baseline were observed in ANTHEM-HF in standard deviation in normal-to-normal R-R intervals (94 ± 26 to 111 ± 50 vs. 146 ± 48 to 130 ± 52 ms; P < 0.001), left ventricular ejection fraction (32 ± 7 to 37 ± 0.4 vs. 31 ± 6 to 33 ± 6; P < 0.05), and Minnesota Living with Heart Failure mean score (40 ± 14 to 21 ± 10 vs. 44 ± 22 to 36 ± 21; P < 0.002). When compared with INOVATE-HF, greater improvement in 6-min walk distance was observed in ANTHEM-HF (287 ± 66 to 346 ± 78 vs. 304 ± 111 to 334 ± 111 m; P < 0.04). CONCLUSIONS In this post-hoc analysis, differences in patient demographics were seen and may have caused the differential responses in symptoms and function observed in association with VNS. Major differences in technology platforms, neural targets, VNS delivery, and HR and HR variability responses could have also potentially played a very important role. Further study is underway in a randomized controlled trial with these considerations in mind.
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Affiliation(s)
- Inder S. Anand
- Division of CardiologyUniversity of MinnesotaMinneapolisMNUSA
| | | | - Helmut U. Klein
- Division of CardiologyUniversity of Rochester Medical CenterRochesterNYUSA
| | - Douglas L. Mann
- Center for Cardiovascular ResearchWashington University School of MedicineSaint LouisMOUSA
| | - Jeffrey L. Ardell
- UCLA Neurocardiology Program of ExcellenceUniversity of CaliforniaLos AngelesCAUSA
| | | | - Joseph M. Massaro
- Department of Biostatistics, School of Public HealthBoston UniversityBostonMAUSA
| | | | | | | | - Javed Butler
- Department of MedicineUniversity of Mississippi Medical CenterJacksonMSUSA
| | - John D. Parker
- University of TorontoUniversity Health NetworkTorontoOntarioCanada
| | - John R. Teerlink
- Section of Cardiology, San Francisco Veterans Affairs Medical Center and School of MedicineUniversity of CaliforniaSan FranciscoCAUSA
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Konstam MA, Udelson JE, Butler J, Klein HU, Parker JD, Teerlink JR, Wedge PM, Saville BR, Ardell JL, Libbus I, DiCarlo LA. Impact of Autonomic Regulation Therapy in Patients with Heart Failure. Circ Heart Fail 2019; 12:e005879. [DOI: 10.1161/circheartfailure.119.005879] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Background:
The ANTHEM-HFrEF (Autonomic Regulation Therapy to Enhance Myocardial Function and Reduce Progression of Heart Failure with Reduced Ejection Fraction) pivotal study is an adaptive, open-label, randomized, controlled study evaluating whether autonomic regulation therapy will benefit patients with advanced HFrEF. While early-phase studies have supported potential use of vagus nerve stimulation to deliver autonomic regulation therapy for HFrEF, results of larger clinical trials have been inconsistent. The ANTHEM-HFrEF study uses a novel design, with adaptive sample size selection, evaluating effects on morbidity and mortality as well as symptoms and function.
Methods:
The ANTHEM-HFrEF study will randomize patients (2:1) to autonomic regulation therapy plus guideline-directed medical therapy, or guideline-directed medical therapy alone. The morbidity and mortality trial utilizes a conventional frequentist approach for analysis of the primary outcome end point—reduction in the composite of cardiovascular death or first HF hospitalization—and a Bayesian adaptive approach toward sample size selection. Embedded within the ANTHEM-HFrEF study is a second trial evaluating improvement in symptoms and function. Symptom/function success will require meeting 2 risk-related conditions (trend for reduced cardiovascular death/HF hospitalization and sufficient freedom from device-related serious adverse events) and 3 efficacy end point components (changes in left ventricular EF, 6-minute walk distance, and Kansas City Cardiomyopathy Questionnaire overall score).
Conclusions:
Vagus nerve stimulation remains a promising, yet unproven treatment in HFrEF. A successful ANTHEM-HFrEF pivotal study would provide an important advance in HFrEF treatment and offer a model for expediting evaluation of new therapies.
Clinical Trial Registration:
URL:
http://www.clinicaltrials.gov
. Unique identifier: NCT03425422.
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Affiliation(s)
- Marvin A. Konstam
- The CardioVascular Center at Tufts Medical Center, Boston, MA (M.A.K., J.E.U.)
| | - James E. Udelson
- The CardioVascular Center at Tufts Medical Center, Boston, MA (M.A.K., J.E.U.)
| | - Javed Butler
- Department of Medicine, University of Mississippi Medical Center, Jackson, MS (J.B.)
| | - Helmut U. Klein
- Department of Medicine, University of Rochester Medical Center, NY (H.U.K.)
| | - John D. Parker
- University of Toronto, Mount Sinai Hospital, Division of Cardiology, Sinai Health Systems and University Health Network, Toronto, Canada (J.D.P.)
| | - John R. Teerlink
- Section of Cardiology, San Francisco Veterans Affairs Medical Center and School of Medicine, University of California (J.R.T.)
| | | | - Benjamin R. Saville
- Berry Consultants LLC, Austin TX and Department of Biostatistics, Vanderbilt University, Nashville TN (B.R.S.)
| | - Jeffrey L. Ardell
- Neurocardiology Center, University of California, Los Angeles (J.L.A.)
| | - Imad Libbus
- LivaNova USA Incorporated, Houston, TX (I.L., L.A.D.)
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25
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Premchand RK, Sharma K, Mittal S, Monteiro R, Libbus I, Ardell JL, Gregory DD, KenKnight BH, Amurthur B, DiCarlo LA, Anand IS. Background pharmacological therapy in the ANTHEM-HF: comparison to contemporary trials of novel heart failure therapies. ESC Heart Fail 2019; 6:1052-1056. [PMID: 31339232 PMCID: PMC6816059 DOI: 10.1002/ehf2.12484] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 05/06/2019] [Accepted: 06/01/2019] [Indexed: 12/11/2022] Open
Abstract
AIMS Clinical trials of new heart failure (HF) therapies administer guideline-directed medical therapy (GDMT) as background pharmacologic treatment (BPT). In the ANTHEM-HF Pilot Study, addition of autonomic regulation therapy to GDMT significantly improved left ventricular function, New York Heart Association (NYHA) class, 6 min walk distance, and quality of life in patients with HF with reduced ejection fraction (HFrEF). A post hoc analysis was performed to compare BPT in ANTHEM-HF with two other trials of novel HF therapies: the PARADIGM-HF study of sacubitril-valsartan and the SHIFT study of ivadrabine. All three studies evaluated patients with HFrEF, and the recommendations for use of GDMT were similar. A left ventricular ejection fraction ≤40% was required for entry into ANTHEM-HF and PARADIGM-HF and ≤35% for SHIFT. NYHA 2 or 3 symptoms were required for entry into ANTHEM-HF, and patients with predominantly NYHA 2 or 3 symptoms were enrolled in PARADIGM-HF and SHIFT. METHODS AND RESULTS Data on BPT were obtained from peer-reviewed publications and the public domain. Pearson's χ2 test was used to evaluate differences in proportions, and Student's unpaired t-test was used to evaluate differences in mean values. The minimum period of stable GDMT required before randomization was longer in ANTHEM-HF: 3 months vs. 1 month in PARADIGM-HF and SHIFT, respectively. When compared with PARADIGM-HF and SHIFT, more patients in ANTHEM-HF received beta-blockers (100% vs. 93% and 89%, P < 0.04 and P < 0.007) and mineralocorticoid receptor antagonists (75% vs. 55% and 61%, P < 0.002 and P < 0.03). More patients in PARADIGM-HF received an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker than in ANTHEM-HF or SHIFT (100% vs. 85%, P < 0.0001, and 100% vs. 91%, P < 0.001), which was related to PARADIGM's design. When beta-blocker doses in ANTHEM-HF and SHIFT were compared, significantly fewer patients in ANTHEM-HF received doses ≥100% of target (10% vs. 23%, P < 0.02), and fewer patients tended to receive doses ≥50% of target (17% vs. 26%, P = 0.11). When ANTHEM-HF and PARADIGM-HF were compared, more patients in ANTHEM-HF tended to receive doses ≥100% of target (10% vs. 7%, P = 0.36), and fewer patients tended to receive doses ≥50% of target (17% vs. 20%, P = 0.56). CONCLUSIONS Background treatment with GDMT in ANTHEM-HF compared favourably with that in two other contemporary trials of new HF therapies. The minimum period of stable GDMT required before randomization was longer, and GDMT remained unchanged for the study's duration. These findings serve to further support the potential role of autonomic regulation therapy as an adjunct to GDMT for patients with HFrEF.
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Affiliation(s)
| | - Kamal Sharma
- Sanjivani Super Specialty Hospitals, Ahmedabad, India
| | | | | | | | | | | | | | | | | | - Inder S Anand
- University of Minnesota (Emeritus), Minneapolis, MN, USA
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26
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Romero-Ugalde HM, Le Rolle V, Bonnet JL, Henry C, Mabo P, Carrault G, Hernandez AI. Closed-Loop Vagus Nerve Stimulation Based on State Transition Models. IEEE Trans Biomed Eng 2018; 65:1630-1638. [DOI: 10.1109/tbme.2017.2759667] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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27
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Beaumont E, Campbell RP, Andresen MC, Scofield S, Singh K, Libbus I, KenKnight BH, Snyder L, Cantrell N. Cervical vagus nerve stimulation augments spontaneous discharge in second- and higher-order sensory neurons in the rat nucleus of the solitary tract. Am J Physiol Heart Circ Physiol 2017; 313:H354-H367. [PMID: 28476920 DOI: 10.1152/ajpheart.00070.2017] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 05/01/2017] [Accepted: 05/01/2017] [Indexed: 02/07/2023]
Abstract
Vagus nerve stimulation (VNS) currently treats patients with drug-resistant epilepsy, depression, and heart failure. The mild intensities used in chronic VNS suggest that primary visceral afferents and central nervous system activation are involved. Here, we measured the activity of neurons in the nucleus of the solitary tract (NTS) in anesthetized rats using clinically styled VNS. Our chief findings indicate that VNS at threshold bradycardic intensity activated NTS neuron discharge in one-third of NTS neurons. This VNS directly activated only myelinated vagal afferents projecting to second-order NTS neurons. Most VNS-induced activity in NTS, however, was unsynchronized to vagal stimuli. Thus, VNS activated unsynchronized activity in NTS neurons that were second order to vagal afferent C-fibers as well as higher-order NTS neurons only polysynaptically activated by the vagus. Overall, cardiovascular-sensitive and -insensitive NTS neurons were similarly activated by VNS: 3/4 neurons with monosynaptic vagal A-fiber afferents, 6/42 neurons with monosynaptic vagal C-fiber afferents, and 16/21 polysynaptic NTS neurons. Provocatively, vagal A-fibers indirectly activated C-fiber neurons during VNS. Elevated spontaneous spiking was quantitatively much higher than synchronized activity and extended well into the periods of nonstimulation. Surprisingly, many polysynaptic NTS neurons responded to half the bradycardic intensity used in clinical studies, indicating that a subset of myelinated vagal afferents is sufficient to evoke VNS indirect activation. Our study uncovered a myelinated vagal afferent drive that indirectly activates NTS neurons and thus central pathways beyond NTS and support reconsideration of brain contributions of vagal afferents underpinning of therapeutic impacts.NEW & NOTEWORTHY Acute vagus nerve stimulation elevated activity in neurons located in the medial nucleus of the solitary tract. Such stimuli directly activated only myelinated vagal afferents but indirectly activated a subpopulation of second- and higher-order neurons, suggesting that afferent mechanisms and central neuron activation may be responsible for vagus nerve stimulation efficacy.
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Affiliation(s)
- Eric Beaumont
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee;
| | - Regenia P Campbell
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee
| | | | - Stephanie Scofield
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee
| | - Krishna Singh
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee.,James H. Quillen Veterans Affairs Medical Center, Johnson City, Tennessee; and
| | | | | | - Logan Snyder
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee
| | - Nathan Cantrell
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee
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